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3kw bldc motorcycle conversion issues/questions
Motolittle:
Hello my friends, this is my first post to this forum.
I recently just purchased the 3kw 72 volt golden motor bldc and the corresponding 72volt 220 amp vector speed controler. I also purchased a 72 volt lithium-ion 18AH pack that has 50 amp continuous BMS and 100amp max burst.
This is all going in a Yamaha xt350 frame that I am converting to work. I already aquired a 10 tooth front sprocket and a custom 67 tooth rear sprocket.
The issue I am having is that after wiring it all up for testing I am running into some issues...
When I give it throttle about 1/2 the time the motor spins and the other half of the time the motor hums a little bit and will not turn... this is all with no load on the motor... but if I move the driveshaft about a 1/8th turn it will proceed to work until stopped again and it will not go unless I turn it by hand again.
I have connected the system to a pc using the golden motor USB cable and the most current online program. I have changed parameters and settings but the symptoms do not change. I even re loaded the factory settings to make sure that was not it.
To clarify the symptom: when I plug in the battery andturn it on and twist the throttle the motor does not spin (no load). It stutters and hums a little bit. If I spin the motor by hand a small amount and give it throttle it starts to spin and seems to work fine until it stops again and won't start till I spin it again.
I have tested my battery voltage is all good and the motor controller downloads to the computer just fine and seems to be working properly. My question is in the motor. I have tested the Hall sensors with a voltmeter and am confused with my reading. Normal Hall sensors are either off at 0 volts or on about 5 volts when the motor is spun by hand. My readings are as followed for all 3: off voltage is measuring .012v for all sensors and only 3.042volts. To me it seems that all the Hall sensors are bad... but this is a brand new motor.
I can post my parameters from the programming if needed but at this point I need help to figure out what it is. I can test anything you all may want me to test. Thank you in advance for your help
-nick
Bikemad:
Hi Nick andto the forum.
When the motor refused to turn on its own, did you notice any regular flashes from the controller's LED indicator light, if so, how many regular flashes were there?
Are you using a GM throttle?
I'm not sure if an incorrect throttle might put too much load on the +5V supply which could account for the lower voltage reading on the motor's Hall sensors, as I would be very surprised if all three of the Hall sensors were "bad". :-\
It would be interesting to see what the voltage reading on the +5V feed to the Hall sensors was.
Check that your Phase wires are connected to the correct terminals on the controller:
The standard Phase wire configurations are shown below:
U = Yellow
V = Green
W = Blue
If you need to reverse the motor's default direction of rotation to suit your particular installation, take a look at this post for more details.
Alan
Motolittle:
Thank you for the swift response!
The only blinking from the controller is the single blink when I power on using the e-lock. It does not throw any codes that I have seen. The throttle I am using is the standard golden motor 48 volt full twist throttle. I know I use the 72 volt system but Gary from golden motor Canada (where I purchased everything) said that was the only throttle they offer and just not to use the LED battery indicator.
When the motor doesn't spin (under no load) it just hums a little and won't move till I turn it with my hand than it spins up but still seems weak to me for what the system is supposed to be.
Does a 72 volt 18ah battery sound insufficient for this system ? I don't think the battery is the cause of the motor not wanting to spin.
Also my phase wires are all correct to the diagram and my motor spins in the counterclockwise directions when it wants to spin. Is this normal motor direction?
What are some other ways to test the motor... and the Hall sensors? I am trying to do all testing that I can because I don't want to return it but will if I need to. Thank you so much.
Bikemad:
The GM throttle should be fine with the LED battery gauge disconnected, and the battery should have adequate output for a 3kW motor (72V @ 50A = 3.6kW and @ 100A = 7.2kW).
Check out this topic regarding a similar setup with intermittent starting.
Unfortunately, we never found out what was causing the problem as the original poster stopped responding. ::)
It is difficult to say whether the humming is due to an incorrect Phase wire/Hall sensor configuration, controller fault, or possibly a very low starting current, but something is definitely wrong.
I would have expected the motor to run in a clockwise rotation (when viewed from the output shaft end) which is opposite to what you have described. :-\
I also recall a similar problem regarding occasional non-starting of a 5kW motor (but only when it stopped in certain positions) which turned out to be a faulty controller.
You can perform a simple test on the phase wires and stator windings by disconnecting the phase wires from the controller, touching any two phase wires together, and then trying to spin the motor shaft by hand.
If the two phase wires (and windings) are all OK, the shaft should be difficult to spin as the shorted phase wires will cause an electromagnetic dynamic braking effect.
The level of resistance should be identical with all three combinations of pairs touched together (Yellow/Blue, Blue/Green and Green/Yellow).
I have not tried this, but it might be possible to measure the voltage output on the phase wire terminals of the controller (with the Hall sensors connected, but the phase wires disconnected) by applying the throttle while turning the motor by hand.
If it works, I would expect the voltage reading to be similar (and the polarity of the reading should also alternate every 45 degrees) with all three combinations of pairs being measured (U/V, V/W and W/U).
This might not work as the controller may simply produce an error code if it is unable to sense any current flow because the phase wires are not connected, but if it does, you might be able to home in on any anomalies (e.g. if one pair has a different voltage reading or does not change polarity as expected etc.)
If you cannot find anything obvious, perhaps Gary could test your controller on another motor to check its operation.
Alan
Motolittle:
Thank you Alan for the Info.
I tested the motor windings as you described and they all feel similar and no irregularities.
I changed around the phase wires from standard configuration because standard phase setup was spinning counterclockwise for me and 1 configuration did not work but 1 configuration did work and made the motor spin clockwise as you said. I am leaning towards the Hall wire and phase wires not being right as my problem as of now but I need to test more.
Unfortunately I could not connect the motor controller to the computer because I kept getting time out error... never had that before...
I will keep testing and will need to put it into counterclockwise rotation no matter what so I will have to mess with the Hall wires.
If you think of anything else let me know and I will hope to post back soon!
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